1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to a balance filter packaging chip having a balun mounted therein and a manufacturing method thereof, and more particularly, to a balance filter packaging chip having a balun mounted therein and a manufacturing method thereof, wherein the balun is fabricated on a packaging substrate so that a chip size can be reduced, and a manufacturing process thereof can be simplified.
2. Description of the Related Art
A balun (balance to unbalance transformer) is a matching transformer used for preventing the break of ground balance of a balanced circuit when a circuit balanced to the ground is coupled with an amplifier circuit of which one end is grounded, or for connecting a circuit balanced to the ground to an unbalanced circuit such as a coaxial cable in a VHF (Very High Frequency) band transmission circuit.
A filter is one type of electronic circuits that passes only the signals of a desired waveform, filtering those of an undesired waveform. Generally, the filter is constructed with a combination of inductance L and capacitance C. A filter employing an element such as a Lecher wire or a coaxial cable is used in a VHF band of very high frequencies, and a waveguide filter is used in microwave bands of frequencies higher than frequencies of the VHF band.
In addition, filters of special purpose include a CR filter having capacitance and resistance, a crystal filter using mechanical resonance, a mechanical filter, and the like. The filters by function are categorized into an LPF (Low Pass Filter) passing only signals below a certain frequency, a HPF (High Pass Filter) passing only signals above a certain frequency, a BPF (Band Pass Filter) passing signals of a certain frequency band, and a BEF (Band Elimination Filter) suppressing only signals of a certain frequency band.
FIG. 1 is a block diagram for showing a configuration of conventional balun and balance filter.
As shown in FIG. 1, an antenna 10 receives signals transmitted in a wireless manner and transmits the received signals to a balun 20. The balun 20 converts the wireless signal received from the antenna 10 into two signals having a phase difference of 180 degrees each other, and outputs the two signals to a balance filter 30.
Since the two signals having a phase difference of 180 degrees each other are inputted to the balance filter 30, the balance filter is superior to an unbalance filter in terms of power efficiency. Therefore, the balance filter 30 consumes less battery power than the unbalance filter, and does not require large signal amplitude so that relatively less noise occurs. Owing to such advantages, the use of the balun and the balance filter are required.
The conventional technology manufactures the balun and the balance filter separately and then connects them together in a hybrid method, or manufactures the balun and the balance filter together through an integration process. The conventional methods cause problems in that an element size becomes large or the product yield goes lower due to a complicated process since the filter is processed together.